Farm Table says:
Effect of Topically Applied Anaesthetic Formulation on the Sensitivity of Scoop Dehorning Wounds in Calves
What is the problem?
Dehorning reduces the risk of injury to other livestock and workers involved and costs the Australian beef industry $30 million a year because of bruising. Dehorning is a necessity to minimise profit loss, however there are concerns over animal welfare, leading researchers to investigate an effective anaesthetic that farmers can apply themselves.
What did research involve?
Research involved two trials with applications of different treatments of anaesthetic, after dehorning, while measuring the pain response (to mechanical touch).
Trial 1: One of two treatments randomly assigned to 21 female dairy calves aged 8-24 weeks
- post-op anaesthetic powder (DTAP)
- post-op anaesthetic ethanol liquid/spray (DTAE)
Trial 2: One of four treatments randomly assigned to 36 male and female calves aged 16-20 weeks
- pre-op nerve block (DCB)
- post-op DTAE
- post-op anaesthetic gel (DTAG)
- sham/faked dehorning (CON)
Pain response was rated from 0-3 (no response – severe response i.e. jerking head away).
- DTAP was less effective as an anaesthetic than DTAE after 90 minutes. The effectiveness of DTAP as an anaesthetic continued to drop after 90 minutes suggesting it loses its effect quickly. It was also more difficult to apply; there was a lot of wastage, especially if it was windy.
- As expected, the sham (faked) dehorning calves showed the least receptive response.
- DCB supressed the pain response within the first hour, keeping it level with the sham treatment. However, after 2 hours the pain response increased.
- DTAG and DTAE pain responses increased 2 to 4 hours post-op. After that they both did not change up until 6 hours. This suggests that there was a delayed effect. The DTAE contained higher amounts of anaesthetic, yet the gel added a layer over the wound, protecting it.
There were no significant differences in pain response for DCB, DTAG and DTAE up until 6 hours.
Potential products for an easy applicable anaesthetic include: powdered anaesthetic, ethanol spray anaesthetic or a gel anaesthetic. It is hoped that farmers wanting to dehorn their calves could purchase and apply these products themselves, and that they are on par with technical anaesthetic. However, this paper suggest further research needs to be completed, including longer trial periods (up to 24 hours).
This paper was summarised by Jeremy Murphy (Agricultural Science Student – La Trobe University) and reviewed by Nickala Best (PhD Student (La Trobe University). Learn more about Jeremy and Nickala here.